In a large microwave-safe bowl, melt margarine or butter and marshmallows in a microwave set on HIGH for 2 minutes, stirring after 1 minute. Stir until mixture is smooth.
Allow cereal mixture to cool slightly. With buttered hands, shape cereal mixture into mugs, reserving small portions of cereal mixture for handles. Attach handle to mug with frosting. Add chocolate syrup for 'coffee' colour.
In keeping with good allergy practices, we remind you to be aware of allergens and to check labels on any packaged goods used. This recipe has been tested using Kellogg's* products. Results with other products may vary.